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Systematic study of cluster radioactivity within the Generalized Liquid Drop Model
Jun-Gang Deng, Jun-Hao Cheng, Xiao-Jun Bao, Hong-Fei Zhang
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CDATA[The cluster radioactivity is studied within the Generalized Liquid Drop Model (GLDM), in which the shell correction energy, the pairing energy, and the cluster preformation factor are considered. The calculations show significant improvements and can reproduce the experimental data within a factor of 8.04 after the consideration of these physical effects. In addition, the systematic trend of cluster preformation factors \begin{document}$ P_c $\end{document} is discussed in terms of the \begin{document}$ N_p N_n $\end{document} scheme to study the influence of valence proton-neutron interaction and shell effect on cluster radioactivity. It is strikingly found that the \begin{document}$ \log_{10}{P_c} $\end{document} is linearly related to the \begin{document}$ N_p N_n $\end{document}. It is in agreement with the recent work [L. Qi et al., Phys. Rev. C 108, 014325 (2023)], in which \begin{document}$ \log_{10}{P_c} $\end{document}, obtained by using different theoretical models and treatment methods from this work, also has a linear relationship with \begin{document}$ N_p N_n $\end{document}. Combined with recent work by Qi et al., this work suggests that the linear relationship between \begin{document}$ \log_{10}{P_c} $\end{document} and \begin{document}$ N_p N_n $\end{document} is model-independent and that both the shell effect and the valence proton-neutron interaction play essential roles in cluster radioactivity. An analytical formula is proposed to calculate the cluster preformation factor based on the \begin{document}$ N_p N_n $\end{document} scheme. In addition, the cluster preformation factors and cluster radioactivity half-lives of some heavy nuclei are predicted, which can provide references for experiments in the future.
Investigation for $ { \boldsymbol D^{\bf +} \boldsymbol\to \boldsymbol\pi^{\bf +} \boldsymbol\nu\bar{\boldsymbol\nu}} $ decay process within QCDSR approach
Yu Chen, Hai-Bing Fu, Tao Zhong, Sheng-Bo Wu, Dong Huang
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In the paper, we investigate the charmed meson rare decay process \begin{document}$ D^+ \to \pi^+\nu\bar\nu $\end{document} by using the QCD sum rules approach. Firstly, the pion twist-2, 3 distribution amplitudes (DA) moments \begin{document}$ \langle\xi_{2;\pi}^n\rangle|_\mu $\end{document} and \begin{document}$ \langle \xi_{3;\pi}^{(p,\sigma),n}\rangle|_\mu $\end{document} are calculated up to 10th-order and fourth-order in the QCD sum rules under background field theory respectively. After constructing the light-cone harmonic oscillator model for pion twist-2, 3 DAs, we get their behaviors by matching the calculated ξ-moments. Then, the \begin{document}$ D\to \pi $\end{document} transition form factors (TFFs) are calculated by using QCD light-cone sum rules approach. The vector form factor at large recoil region is \begin{document}$ f_+^{D\to\pi}(0) = 0.627^{+0.120}_{-0.080} $\end{document}. By taking the rapidly \begin{document}$ z(q^2,t) $\end{document} converging simplified series expansion, we present the TFFs and the corresponding angular coefficients in the whole squared momentum transfer physical region. Based on the Non-standard neutrino interactions, the \begin{document}$ D^+ \to \pi^+ \nu\bar\nu $\end{document} decay can be related to \begin{document}$ \bar D^0 \to \pi^+ e\bar \nu_e $\end{document} decay indirectly. Thus, we firstly display the semileptonic decay process \begin{document}$ \bar D^0 \to \pi^+ e\bar \nu_e $\end{document} differential decay widths and branching fraction with \begin{document}$ {\cal B}(\bar D^0\to\pi^+e\bar\nu_e) = 0.308^{+0.155}_{-0.066} \times 10^{2} $\end{document}. The \begin{document}$ \bar D^0\to\pi^+e\bar\nu_e $\end{document} differential/total predictions for forward-backward asymmetry, \begin{document}$ q^2 $\end{document}-differential flat terms and lepton polarization asymmetry are also given. Then, prediction for the \begin{document}$ D^+ \to \pi^+ \nu\bar\nu $\end{document} branching fraction is \begin{document}$ {\cal B}(D^+ \to \pi^+ {\nu }{\bar\nu}) = 1.85^{+0.93}_{-0.46}\times10^{-8} $\end{document}.
A study of U-isotope ground state properties with Covariant Energy Density Functional
Junchen Wang, Yuan Tian, Ruirui Xu, Ying Cui, Xi Tao, Xiaodong Sun, Zhi Zhang, Yue Zhang, Yinlu Han, Zhigang Ge, Nengchuan Shu
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In this paper we have systematically analyzed the ground state of uranium isotopes from 225 to 240. In our calculations, we used the covariant energy density functional of density dependent meson exchange interaction (DD-ME2) with separable pairing interaction (TMR). Using the multiple deformation constraint, we calculate the potential energy surface (PES) of the uranium isotopes for both even-even and even-odd nuclei with quadrupole and octupole deformation. By comparison with experimental data and Hartree-Fock-Bogoliubov calculations with Gogny D1S, the ground state of the uranium isotopes is always preferred to reflection-asymmetric deformation with our calculation.
QCD Sum Rule study of JP = 1± exotic states with two heavy quarks in the molecular picture
T.M. Aliev, S. Bilmis, M. Savcı
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In this study, the spectroscopic parameters of the exotic molecular states composed of mesons containing two heavy quarks (scalar - axial and pseudoscalar - axial meson combinations) are investigated within QCD sum rules. Our findings reveal that the molecular states containing charm quarks do not form bound states, whereas the states with b-quarks can form the exotic molecular states. This observation has significant implications for understanding the structure of these exotic states.
B − L model with D4 × Z4 × Z2 symmetry for fermion mass hierarchies and mixings
V. V. Vien
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We construct a gauge \begin{document}$ B-L $\end{document} model with \begin{document}$ D_4\times Z_4\times Z_2 $\end{document} symmetry that can explain the quark and lepton mass hierarchies and their mixings with the realistic CP phases via the type-I seesaw mechanism. Six quark mases, three quark mixing angles and CP phase in the quark sector can get the central values and Yukawa couplings in the quark sector are diluted a range of three orders of magnitude difference by the perturbation theory at the first order. For neutrino sector, the smallness of neutrino mass is achieved by the Type-I seesaw mechanism. Both inverted and normal neutrino mass hierarchies are in consistent with the experimental data. The prediction for the sum of neutrino masses for normal and inverted hierarchies, the effective neutrino masses and the Dirac CP phase are well consistent with all the recent limits.
Precise determination of the top-quark on-shell mass ${\boldsymbol M_t}$ via its scale-invariant perturbative relation to the top-quark ${\overline{\bf MS}}$ mass ${{\overline {\boldsymbol m}}_{\boldsymbol t}({\overline {\boldsymbol m}}_{\boldsymbol t})}$
Xu-Dong Huang, Xing-Gang Wu, Xu-Chang Zheng, Jiang Yan, Zhi-Fei Wu, Hong-Hao Ma
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It has been shown that the principle of maximum conformality (PMC) provides a systematic way to solve conventional renormalization scheme and scale ambiguities. The scale-fixed predictions for physical observables using the PMC are independent of the choice of renormalization scheme – a key requirement of renormalization group invariance. In the paper, we derive new degeneracy relations based on the renormalization group equations that involve both the usual β-function and the quark mass anomalous dimension \begin{document}$ \gamma_m $\end{document}-function, respectively. These new degeneracy relations lead to an improved PMC scale-setting procedures, such that the correct magnitudes of the strong coupling constant and the \begin{document}$ \overline{{\rm{MS}}} $\end{document}-running quark mass can be fixed simultaneously. By using the improved PMC scale-setting procedures, the renormalization scale dependence of the \begin{document}$ \overline{{\rm{MS}}} $\end{document}-on-shell quark mass relation can be eliminated systematically. Consequently, the top-quark on-shell (or \begin{document}$ \overline{{\rm{MS}}} $\end{document}) mass can be determined without conventional renormalization scale ambiguity. Taking the top-quark \begin{document}$ \overline{{\rm{MS}}} $\end{document} mass \begin{document}$ {\overline m}_t({\overline m}_t)=162.5^{+2.1}_{-1.5} $\end{document} GeV as the input, we obtain \begin{document}$ M_t\simeq 172.41^{+2.21}_{-1.57} $\end{document} GeV. Here the uncertainties are combined errors with those also from \begin{document}$ \Delta \alpha_s(M_Z) $\end{document} and the approximate uncertainty stemming from the uncalculated five-loop terms predicted through the Padé approximation approach.
Mass suppression effect in QCD radiation and hadron angular distribution in jet
Chuan-Hui Jiang, Hai Tao Li, Shi-Yuan Li, Zong-Guo Si
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The finite mass of the heavy quark suppresses the collimated radiations, which is generally referred to as the dead cone effect. In this paper, we study the distribution of hadron multiplicity over the hadron opening angle with respect to the jet axis in various flavors of jets. The corresponding measurement can be the most straightforward and simplest to explore the dynamical evolution of the radiations in the corresponding jet, which can expose the mass effect. We also propose the transverse energy-weighted angular distribution which sheds light on the interplay between perturbative and nonperturbative effects in the radiation. With Monte-Carlo simulations, our calculation shows that the dead cone effect can be clearly seen by taking the ratio between the b jet and the light-quark (inclusive) jet, promising to be measured at the LHC in the future.
Optimization of performance of the KM2A full array using the Crab Nebula
Zhen Cao, F. Aharonian, Q. An, Axikegu, Y.X. Bai, Y.W. Bao, D. Bastieri, X.J. Bi, Y.J. Bi, J.T. Cai, Q. Cao, W.Y. Cao, Zhe Cao, J. Chang, J.F. Chang, A.M. Chen, E.S. Chen, Liang Chen, Lin Chen, Long Chen, M.J. Chen, M.L. Chen, Q.H. Chen, S.H. Chen, T.L. Chen, Y. Chen, N. Cheng, Y.D. Cheng, M.Y. Cui, S.W. Cui, X.H. Cui, Y.D. Cui, B.Z. Dai, H.L. Dai, Z.G. Dai, Danzengluobu, D. della Volpe, X.Q. Dong, K.K. Duan, J.H. Fan, Y.Z. Fan, J. Fang, K. Fang, C.F. Feng, L. Feng, S.H. Feng, X.T. Feng, Y.L. Feng, S. Gabici, B. Gao, C.D. Gao, L.Q. Gao, Q. Gao, W. Gao, W.K. Gao, M.M. Ge, L.S. Geng, G. Giacinti, G.H. Gong, Q.B. Gou, M.H. Gu, F.L. Guo, X.L. Guo, Y.Q. Guo, Y.Y. Guo, Y.A. Han, H.H. He, H.N. He, J.Y. He, X.B. He, Y. He, M. Heller, Y.K. Hor, B.W. Hou, C. Hou, X. Hou, H.B. Hu, Q. Hu, S.C. Hu, D.H. Huang, T.Q. Huang, W.J. Huang, X.T. Huang, X.Y. Huang, Y. Huang, Z.C. Huang, X.L. Ji, H.Y. Jia, K. Jia, K. Jiang, X.W. Jiang, Z.J. Jiang, M. Jin, M.M. Kang, T. Ke, D. Kuleshov, K. Kurinov, B.B. Li, Cheng Li, Cong Li, D. Li
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The full array of the Large High Altitude Air Shower Observatory (LHAASO) has been in operation since July 2021. For its kilometer-square array (KM2A), we have optimized the selection criteria for very high and ultra-high energy γ-rays, using the data collected from August 2021 to August 2022, resulting in an improvement on significance of the detection in the Crab Nebula of about 15\begin{document}$\%$\end{document} compared with previous cuts. With the implementation of these new selection criteria, the angular resolution is also significantly improved by approximately 10\begin{document}$\%$\end{document} at tens of TeV. Other aspects of the full KM2A array performance, such as the pointing error are also calibrated using the Crab Nebula. The resulting energy spectrum of the Crab Nebula in the energy range of 10-1000 TeV can be well fitted by a log-parabola model, which is consistent with the previous results from LHAASO and other experiments.
Refined symmetry-resolved Page curve and charged black holes
Pan Li, Yi Ling
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The Page curve plotted by the typical random state approximation is not applicable to a system with conserved quantities, such as the evaporation process of a charged black hole during which the electric charge does not radiate out with a uniform rate macroscopically. In this context the symmetry-resolved entanglement entropy may play a significant role in describing the entanglement structure of such a system. We attempt to impose constraints on microscopic quantum states to match with the macroscopic phenomenon of the charge radiation during black hole evaporation. Specifically, we consider a simple qubit system with conserved spin/charge serving as a toy model for the evaporation of charged black holes. We propose refined rules for selecting a random state with conserved quantities to simulate the distribution of charges during the different stages of evaporation, and obtain refined Page curves that exhibit distinct features in contrast to the original Page curve. We find the refined Page curve may have a different Page time and exhibit asymmetric behavior on both sides of the Page time. Such refined Page curves may provide more realistic description for the entanglement between the charged black hole and radiation during the process of evaporation.
Correlation function and the inverse problem in the BD interaction
Hai-Peng Li, Jing-Yu Yi, Chu-Wen Xiao, De-Liang Yao, Wei-Hong Liang, Eulogio Oset
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We carry a study of the correlation functions of the \begin{document}$ B^0 D^+, B^+ D^0 $\end{document} system, which develops a bound state by about \begin{document}$ 40 \;{\rm{MeV}} $\end{document}, using input consistent with the \begin{document}$ T_{cc}(3875) $\end{document} state. Then we face the inverse problem of starting from these correlation functions to determine scattering observables related to the system, including the existence of the bound state and its molecular nature. The important output of the approach is the uncertainty by which these observables can be obtained, assuming errors in the \begin{document}$ B^0 D^+, B^+ D^0 $\end{document} correlation functions typical of current ones in present correlation functions. We observe that it is possible to obtain scattering lengths and effective ranges with relative high precision and the existence of a bound state. While the pole position is obtained with errors of the order of 50% of the binding energy, the molecular probability of the state is obtained with a very small error of the order of 6%. All these findings can serve as motivation to perform such measurements in future runs of high energy hadron collisions.
Sequential decay analysis of 235U(nth,f) reaction using fragmentation approach
Nitin Sharma, Ashutosh Kaushik, Manoj K. Sharma
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Numerous experimental and theoretical observations conclude that the probability of the three fragment emission (ternary fission) or the binary fission increases when one proceeds towards the heavy mass region of nuclear periodic table. There are many factors that affect the fragment emission such as shell effect, deformation, orientation and the fissility parameter, etc. The binary and ternary fission is observed for both ground state as well as excited state of the nuclei. The collinear cluster tripartition (CCT) channel of \begin{document}$ ^{235} $\end{document}U(n\begin{document}$ ^{th} $\end{document},f) reaction is studied and it was observed that the CCT may be a sequential process or a simultaneous emission phenomena. Till now, different approaches are introduced to study the CCT process as a simultaneous process or sequential process, but the decay dynamics of these modes is not fully explored. It will be of further interest to identify the three fragments of the sequential process and to explore their related dynamics using some excitation energy dependent approach. Hence, in present work, an attempt is made to study the sequential decay mechanism of \begin{document}$ ^{235} $\end{document}U(n\begin{document}$ ^{th} $\end{document},f) reaction using quantum mechanical fragmentation theory (QMFT). The decay mechanism is considered in two steps, where initially the nucleus splits into an asymmetric channel. In the second step, the heavy fragment obtained in the first step divides into two fragments. Stage I analysis is done by calculating the fragmentation potential and the preformation probability for the spherical and deformed choice of the decaying fragments. The most probable fragment combination of stage I are identified in view the dips in the fragmentation structure, and the corresponding maxima's of the preformation probability (\begin{document}$ P_0 $\end{document}). The light fragments of the identified decay channels (obtained in step I) find nice agreement with the experimentally observed fragments. The excitation energy of the decay channel is calculated using an iteration process. The sharing of the excitation energy is done using excitation energy dependent level density parameter. The obtained excitation energy of the identified heavy fragments is further used for the fragmentation analysis, and the subsequent binary fragments of the sequential process are obtained. The identified three fragments of the sequential process are in agreement with the experimental observation and are found nearby the neutron or proton shell closure. Finally, the kinetic energy of the observed fragments is calculated and the middle fragment of the CCT mechanism is identified.
TALYS calculation and a short review of the experimental status of proton capture studies on p-nuclei: A guide to future investigation
Indrani Ray, Argha Deb
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TALYS calculations have been performed to obtain the theoretical proton capture cross-sections on the p-nuclei. A short review has been done on the status of the experimental studies of the same. Some basic properties like the Q-values, Coulomb barrier, Gamow peak, Gamow Window, decay properties of the parent and daughter nuclei have been compiled. The various experimental parameters namely, beam energy, beam current, targets, detectors etc. used in the various experimental investigations reported in the literature have been tabulated. TALYS calculations results in the Gamow region have been compared with the corresponding experimental values wherever available. This work is expected to facilitate the planning of the future experiments.
Merger estimates for a disformal Kerr black hole in quadratic degenerate higher-order scalar-tensor theories
Hongxin Jiang, Xinyi Du, Qiyuan Pan, Songbai Chen, Jiliang Jing
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We investigate the main features of the disformal Kerr black hole merger in quadratic degenerate higher-order scalar-tensor (DHOST) theories. For the ringdown stage of the black hole mergers, we find that, for the prograde orbit, the real part of the quasinormal modes (QNMs) decreases with the increase of the disformal parameter, and imaginary part decreases with it except for the Kerr case for large spin parameter. But for the retrograde orbit, the real part increases with the increase of the disformal parameter and imaginary part always decreases with it. For the approximate final spin, we observe that, regardless of the equal spin merger, unequal spin merger and generic spin configuration merger, the final black hole spin always increases with the increase of the disformal parameter. Our results show that the disformal parameter in the disformal Kerr solution and the MOG parameter in the Kerr-MOG case have obviously different effects on the black hole merger, which suggests the differences of these two spacetime structures.
Cross sections for 14 MeV neutron interaction with lutetium isotopes and their theoretical excitation functions
Yueli Song, Fengqun Zhou, Yong Li, Xiaopeng Zhang, Pengfei Ji, Xiaojun Sun
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The reaction cross-sections for the 175Lu(n,p)175Yb, 175Lu(n,α)172Tm, 176Lu(n,α)173Tm, 175Lu(n,2n)174mLu, and 175Lu(n,2n)174gLu reactions at the 13.57, 14.03 14.62 and 14.86 MeV neutron energies were measured by using an activation technique. The theoretical excitation functions of these reactions were calculated by using the Talys-1.95 code. The experimentally obtained reaction cross-section data were analyzed and compared with the literature experimental data, and the evaluated data of five major evaluated nuclear data libraries of IAEA, as well as with the theoretical values based on Talys-1.95. The present data at some neutron energies agree with some of the literature data, and with theoretical values based on Talys-1.95. The consistency of the theoretical curves of excitation functions based on Talys-1.95 with the present and literature data is better than that of the evaluation curves of excitation functions for the 175Lu(n,p)175Yb, 175Lu(n,α)172 Tm, and 176Lu(n,α)173Tm reactions. This work will be helpful to give new evaluated reaction cross-section data on the fusion reactor material lutetium to improve the quality of the neutron-induced reaction cross section data libraries, and advance the related application research.
Probing valence quark width of the proton in deeply virtual Compton scattering at high energies
Wenchang Xiang, Dewen Cao, Daicui Zhou
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We use the refined hot spot model to study the valence quark shape of the proton with the deeply virtual Compton scattering at high energies in the framework of Color Glass Condensate. To investigate the individual valence quark shape, a novel treatment of the valence quark width is employed. We calculate the cross-sections for the coherent and incoherent deeply virtual Compton scattering, for the first time, by using different widths (\begin{document}$ \mathrm{B_u} $\end{document} and \begin{document}$ \mathrm{B_d} $\end{document}) for the profile density distributions of the up and down quarks instead of using the same width as in the literature. We find that the cross-sections calculated with \begin{document}$ \mathrm{B_u \geq B_d} $\end{document} at each collision energy are consistent with each other themselves, which is in agreement with the theoretical expectations. While the ones computed with \begin{document}$ \mathrm{B_u < B_d} $\end{document} show some discrepancies. This outcome implies that the up quark might emit more gluons than the down quark leading to \begin{document}$ \mathrm{B_u \geq B_d} $\end{document} at high energy. The energy impact of the outcome is estimated. Our results show that as the collision energy increases, the aforementioned discrepancies are not only significantly broadened, but also shift to relatively smaller momentum transfer range in the future Electron-Ion Collider (EIC) and Large Hadron Electron Collider (LHeC) energies, which indicates that the EIC and LHeC can provide unprecedented chance to access the shape of the valence quark of the proton.
A study of topological quantities of lattice QCD by a modified DCGAN frame
Lin Gao, Heping Ying, Jianbo Zhang
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A modified deep convolutional generative adversarial network (M-DCGAN) frame is proposed to study the N-dimensional (ND) topological quantities in lattice QCD based on the Monte Carlo (MC) simulations. We construct a new scaling structure including fully connected layers to support the generation of high-quality high-dimensional images for the M-DCGAN. Our results show that the M-DCGAN scheme of the Machine learning should be helpful for us to calculate efficiently the 1D distribution of topological charge and the 4D topological charge density compared with the case by the MC simulation alone.
Teukolsky-like equations with various spins in spherically symmetric spacetime
Ya Guo, Hiroaki Nakajima, Wenbin Lin
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We study the wave equations with various spins on the background of the general spherically symmetric spacetime. We obtain the unified expression of the Teukolsky-like master equations and the corresponding radial equations with the general spins. We also discuss the gauge dependence in the gravitational-wave equations, which have appeared in the previous studies.
Dark energy and matter interacting scenario can relieve H0 and S8 tensions
Li-Yang Gao, She-Sheng Xue, Xin Zhang
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We consider a new cosmological model (named \begin{document}$ \tilde\Lambda $\end{document}CDM) in which the vacuum energy interacts with matter and radiation, and test this model using the current cosmological observations. Using the CMB+BAO+SN (CBS) data set to constrain the model, we find that the \begin{document}$ H_0 $\end{document} and \begin{document}$ S_8 $\end{document} tensions are relieved to \begin{document}$ 2.87\sigma $\end{document} and \begin{document}$ 2.77\sigma $\end{document}, respectively. However, in this case, the \begin{document}$ \tilde\Lambda $\end{document}CDM model is not favored by the data, compared with ΛCDM. We find that when the \begin{document}$ H_0 $\end{document} and \begin{document}$ S_8 $\end{document} data are added into the data combination, the situation is significantly improved. In the CBS+\begin{document}$ H_0 $\end{document} case, we find that the model relieves the \begin{document}$ H_0 $\end{document} tension to \begin{document}$ 0.47\sigma $\end{document}, and in this case, the model is favored over ΛCDM. In the CBS+\begin{document}$ H_0 $\end{document}+\begin{document}$ S_8 $\end{document} case, we get a synthetically best situation in which the \begin{document}$ H_0 $\end{document} and \begin{document}$ S_8 $\end{document} tensions are relived to \begin{document}$ 0.72\sigma $\end{document} and \begin{document}$ 2.11\sigma $\end{document}, respectively. In this case, the model is most favored by the data. Therefore, such a cosmological model can greatly relieve the \begin{document}$ H_0 $\end{document} tension, and at the same time, it can also effectively alleviate the \begin{document}$ S_8 $\end{document} tension.
Different coalescence sources of light nuclei production in Au-Au collisions at ${ \sqrt{\boldsymbol s_{\boldsymbol NN}}=\bf 3 }$ GeV
Rui-Qin Wang, Ji-Peng Lv, Yan-Hao Li, Jun Song, Feng-Lan Shao
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We study the production of light nuclei in the coalescence mechanism in Au-Au collisions at midrapidity at \begin{document}$ \sqrt{s_{NN}}=3 $\end{document} GeV. We derive analytic formulas of momentum distributions of two bodies, three bodies and four nucleons coalescing into light nuclei, respectively. We naturally explain the transverse momentum spectra of the deuteron (d), triton (t), helium-3 (3He) and helium-4 (4He). We reproduce the data of yield rapidity densities, yield ratios and averaged transverse momenta of d, t, 3He and 4He. We give proportions of contributions from different coalescence sources for t, 3He and 4He in their productions. We find that besides nucleon coalescence, nucleon+nucleus coalescence and nucleus+nucleus coalescence may play requisite roles in light nuclei production in Au-Au collisions at \begin{document}$ \sqrt{s_{NN}}=3 $\end{document} GeV.
Gravitational form factors of the proton from near-threshold vector meson photoproduction
Xiao-Yun Wang, Fancong Zeng, Jiyuan Zhang
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We embark on a systematical analysis of the quark and gluon gravitational form factors (GFFs) of the proton, by connecting energy-momentum tensor and the near-threshold vector meson photoproduction (NTVMP). Concretely, the quark contributions of GFFs are determined by global fitting the cross section of the lightest vector meson \begin{document}$ \rho^0 $\end{document} photoproduction. Combined with the gluon GFFs achieved from heavy quarkonium \begin{document}$ J/\psi $\end{document} photoproduction data, the complete GFFs are obtained and compared with the experimental results and Lattice QCD determinations. In addition, we use the Resonances Via Padé (RVP) method based on the Schlessinger Point Method to obtain a model-independent quark D-term distribution by direct analytical continuation of Deep Virtual Compton Scattering experimental data. If errors are considered, the results obtained by RVP are basically consistent with those obtained by NTVMP. Moreover, the comprehensive information on GFFs helps us to uncover the mass distribution and mechanical properties inside the proton. This work is not only an important basis for delving the proton enigmatic properties, but also have significance theoretical guiding for future JLab and EICs experimental measurements.
Study of bending angle and shadow in a new Schwarzschild-like black hole affected by plasma and non-plasma medium
Riasat Ali, Tiecheng Xia, Muhammad Awais, Rimsha Babar
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In this study, we analyze the models of the deflection angle of a new Schwarzschild-like black hole and employ the optical metric of the black hole. To do so, we use the Gaussian curvature of the optical metric and the Gauss-Bonnet theorem, known as the Gibbons-Werner technique, to determine the deflection angle. Furthermore, we examine the deflection angle in the presence of the plasma medium and how the plasma medium affects the deflection angle. The deflection angle of the BH solution in the gauged super-gravity is computed using the Keeton-Petters approach. By utilizing the ray-tracing technique, we investigate the shadow of corresponding black hole and analyze the plots of the deflection angle as well as shadow to check the influence of the plasma and the algebraic thermodynamic parameters on the deflection angle and the shadow.
Molecular components in the J/ψ and the ρ-π puzzle
Xing-Dao Guo, Dian-Yong Chen, Xue-Qian Li, Zhong-Yuan Yuan, Shijing Sang
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Motivated by the large branching fractions of \begin{document}$ J/\psi \to f_0 (1710) \omega/f_0(1710) \phi $\end{document} and the light exotic candidates, we find that there may exist molecular states composed of \begin{document}$ f_0(1710) \omega $\end{document} and \begin{document}$ f_0 (1710) \phi $\end{document}, which correspond to \begin{document}$ X(2440) $\end{document} and \begin{document}$ X(2680) $\end{document} observed in a few decades before. The branching fraction of \begin{document}$ X(2440) $\end{document} and \begin{document}$ X(2680) $\end{document} to various \begin{document}$ PV $\end{document} channels and \begin{document}$ KK\omega(\phi) $\end{document} channels are estimated in the molecular scenario. In addition, the large branching fractions of \begin{document}$ J/\psi \to f_0 (1710) \omega/f_0(1710) \phi $\end{document} indicate the sizable molecular components in the \begin{document}$ J/\psi $\end{document} state. Thus, we consider the \begin{document}$ J/\psi $\end{document} as the supperposition of \begin{document}$ c\bar{c}(1S) $\end{document}, \begin{document}$ f_0(1710) \omega $\end{document} and \begin{document}$ f_0 (1710) \phi $\end{document} molecular states, and these molecular components have significant impact on the light hadron decays of \begin{document}$ J/\psi $\end{document}, which may shield light on the long standing \begin{document}$ \rho-\pi $\end{document} puzzle.
Bubble nucleation in the two-flavor quark-meson model
Junrong Wang, Ziwan Yu, Hong Mao
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We investigate the dynamics of a first-order quark-hadron transition via homogeneous thermal nucleation in the two-flavor quark-meson model. The contribution of the fermionic vacuum loop in the effective thermodynamics potential and phase diagram together with the location of critical end point (CEP) have been obtained in the temperature and chemical potential plane. For a weak and strong first-order phase transition, by taking the temperature as a variable, the critical bubble profiles, the evolutions of the surface tension and the saddle-point action in the presence of a nucleation bubble are numerically calculated in detail when fixing the chemical potentials at \begin{document}$ \mu=306 \mathrm{MeV} $\end{document} and \begin{document}$ \mu=309 \mathrm{MeV} $\end{document}. Our results show that the system could be trapped in the metastable state for a long time as long as the temperature is between the metastable region characterized by the up and low spinodal lines. Moreover, the surface tension at criticality will rise up to about \begin{document}$ 4 \mathrm{MeV/fm^2} $\end{document} when the chemical potential is very high. Such a small value of the surface tension would favor a mixed phase in the cores of compact stars and may have an important implication in astrophysics.
B meson rare decays in the TNMSSM
Hai-Xiang Chen, Sheng-Kai Cui, Ning-Yu Zhu, Zhao-Yang Zhang, Huai-Cong Hu
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We investigate the two loop electroweak corrections to B meson rare decays \begin{document}$ \bar B\rightarrow X_s\gamma $\end{document} and \begin{document}$ B_s^0\rightarrow \mu^+\mu^- $\end{document} in the minimal supersymmetry standard model (MSSM) extension with two triplets and one singlet (TNMSSM). The new particle contents and interactions in the TNMSSM can affect the theoretical predictions of the branching ratios \begin{document}$ {\rm{Br}}(\bar B\rightarrow X_s\gamma) $\end{document} and \begin{document}$ {\rm{Br}}(B_s^0\rightarrow \mu^+\mu^-) $\end{document}, and the corrections from two loop diagrams to the process \begin{document}$ \bar B\rightarrow X_s\gamma $\end{document} can reach around \begin{document}$ 4\% $\end{document}. Considering the latest experimental measurements, the numerical results of \begin{document}$ {\rm{Br}}(\bar B\rightarrow X_s\gamma) $\end{document} and \begin{document}$ {\rm{Br}}(B_s^0\rightarrow \mu^+\mu^-) $\end{document} in the TNMSSM are presented and analyzed. It is found that the results in the TNMSSM can fit the updated experimental data well and the new parameters \begin{document}$ T_{\lambda},\;\kappa,\;\lambda $\end{document} affect the theoretical predictions of \begin{document}$ {\rm{Br}}(\bar B\rightarrow X_s\gamma) $\end{document} and \begin{document}$ {\rm{Br}}(B_s^0\rightarrow \mu^+\mu^-) $\end{document} obviously.
Multiplicity dependence of the freezeout parameters in high energy hadron-hadron collisions
Muhammad Ajaz, Majid Shehzad, Muhammad Waqas, Haifa I. Alrebdi, Momhammad Ayaz Ahmad, Antalov Jagnandan, Shawn Jagnandan, Murad Badshah, Jalal Hasan Baker, Abdul Mosawir Quraishi
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We examined the transverse momentum (\begin{document}$ p_T $\end{document}) spectra of various identified particles, encompassing both light-flavored and strange hadrons (\begin{document}$ \pi^+ + \pi^- $\end{document}, \begin{document}$ K^+ + K^- $\end{document}, \begin{document}$ p + \bar{p} $\end{document}, ϕ, \begin{document}$ K_s^0 $\end{document}, \begin{document}$ \Lambda + \bar{\Lambda} $\end{document}, \begin{document}$ \Xi^- + {\bar{\Xi}}^+ $\end{document}, \begin{document}$ \Omega^- + {\bar{\Omega}}^+ $\end{document}), across different multiplicity classes in proton-proton collisions (p-p) at a center-of-mass energy of \begin{document}$ \sqrt{s} $\end{document} = 7 TeV. Utilizing the Tsallis and Hagedorn models, parameters relevant to the bulk properties of nuclear matter were extracted. Both models exhibit good agreement with experimental data. In our analyses, we observed a consistent decrease in the effective temperature (T) for the Tsallis model and the kinetic or thermal freeze-out temperature (\begin{document}$ T_0 $\end{document}) for the Hagedorn model, as we transition from higher multiplicity (class-I) to lower multiplicity (class-X). This trend is attributed to the diminished energy transfer in higher multiplicity classes. Additionally, the transverse flow velocity (\begin{document}$ \beta_T $\end{document}) experiences a decline from class-I to class-X. The normalization constant which represents the multiplicity of produced particles is observed to decrease as we move towards higher multiplicity classes. While the effective and kinetic freeze-out temperatures, as well as the transverse flow velocity, show a mild dependency on multiplicity for lighter particles, this relationship becomes more pronounced for heavier particles. The multiplicity parameter for heavier particles is noted to be smaller in comparison to lighter particles, indicating a greater abundance of lighter hadrons compared to the heavier ones. Various particle species are observed to undergo decoupling from the fireball at distinct temperatures: lighter particles exhibit lower temperatures, while heavier ones show higher temperatures, thereby supporting the concept of multiple freeze-out scenarios. Moreover, we identified a positive correlation between the kinetic freeze-out temperature and transverse flow velocity, a scenario where particles experience stronger collective motion at higher freeze-out temperature. The reason for this positive correlation is that as the multiplicity increases, more energy is transferred into the system. This heightened energy causes greater excitation and pressure within the system, leading to a quick expansion.
Black Hole Shadows in Einstein-Bel-Robinson Gravity
B. Hamil, B. C. Lütfüoğlu
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Gravity models given by higher-order scalar curvature corrections are believed to bear important consequences. The Einstein-Bel-Robinson gravity, with quartic curvature modification, motivated Sajadi et al to explore static spherically symmetric black hole solutions with perturbative methods. In this paper, inspired by their work, we investigate AdS black hole shadows in EBR gravity. Moreover, we demonstrate how the gravity parameter alters the energy emission rate. Finally, we handle the same problem in the presence of plasma, since the black holes are thought to be surrounded by a medium that changes the geodesic of photons.
A scheme to fix multiple solutions in amplitude analyses
Yuanning Gao, Tianze Rong, Zhenwei Yang, Chenjia Zhang, Yanxi Zhang
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Decays of unstable heavy particles usually involve the coherent sum of several amplitudes, like in a multiple slit experiment. Dedicated amplitude analysis techniques have been widely used to resolve these amplitudes for a better understanding of the underlying dynamics. For special cases, where two spin-1/2 particles and two (pseudo-)scalar particles are present in the process, multiple equivalent solutions are found due to intrinsic symmetries in the summed probability density function. In this paper, the problem of multiple solutions is discussed and a scheme to overcome this problem is proposed by fixing some free parameters. Toys are generated to validate the strategy. A new approach to align helicities of initial- and final-state particles in different decay chains is also introduced.
Systematic study of cluster radioactivity in trans-lead nuclei within various versions of proximity potential formalisms
Xiao Liu, Jie-Dong Jiang, Xi-Jun Wu, Xiao-Hua Li
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In this work, based on the framework of the Coulomb and proximity potential model (CPPM), we systematically study the cluster radioactivity half-lives of 26 trans-lead nuclei by considering the cluster preformation probability which is found to possess a simple mass dependence on the emitted cluster by R. Blendowske and H. Walliser [Phys. Rev. Lett. 61, 1930(1988)]. Meanwhile, we investigate 28 different versions of the proximity potential formalisms, which are the most complete known proximity potential formalisms and have been proposed for the description of proton radioactivity, two-proton radioactivity, α decay, heavy-ion radioactivity, quasi-elastic scattering, fusion reactions and other applications. The calculated results show that the modified forms of proximity potential 1977 denoted as Prox.77-12 and the proximity potential 1981 denoted as Prox.81 are the most appropriate proximity potential formalisms for the study of cluster radioactivity as the root-mean-square deviation between experimental data and relevant theoretical results obtained are least and the both values are 0.681. For comparison, a universal decay law (UDL) proposed by Qi et al. [Phys. Rev. C 80, 044326 (2009)], a unified formula of half-lives for α decay and cluster radioactivity proposed by Ni et al. [Phys. Rev. C 78, 044310 (2008)] and a scaling law (SL) in cluster decay proposed by Horoi et al. [J. Phys. G 30, 945 (2004)] are also used. In addition, utilizing CPPM with Prox.77-12, Prox.77-1, Prox.77-2 and Prox.81, we predict the half-lives of 51 potential cluster radioactive candidates whose cluster radioactivity is energetically allowed or observed but not yet quantified in NUBASE2020. The predicted results are in the same order of magnitude with those obtained by using the compared semi-empirical and/or empirical formulae. At the same time, the competition between α decay and cluster radioactivity of these predicted nuclei is discussed and it is found that α decay predominates by comparing half-lives.
Pair of dyon production near the magnetized dyonic Reissner-Nordstrom black holes
Haryanto M. Siahaan
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We investigate the phenomenon of pair production of massive scalar particles with magnetic charge near the horizon of a magnetized dyonic Reissner-Nordstrom black hole. The intrinsic symmetry between electric and magnetic quantities in the Einstein-Maxwell equations suggests that the pair can be generated through both Hawking radiation and the Schwinger effect, provided that the Dirac quantization condition is satisfied.
One-loop contributions for ${\boldsymbol h \bf\rightarrow \boldsymbol\ell \bar{\boldsymbol\ell}\gamma}$ and ${{\boldsymbol e}^{\bf -}{\boldsymbol e}^{\bf +}\bf\rightarrow {\boldsymbol h\gamma}}$ in ${{\boldsymbol U}{\bf (1)}_{{\boldsymbol B}{\bf -}{\boldsymbol L}}}$ extension of the standard model
Tran Dzung Tri, Thanh Huy Nguyen, Khiem Hong Phan
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We present one-loop contributing for \begin{document}$ h\rightarrow \ell \bar{\ell}\gamma $\end{document} with \begin{document}$ \ell =\nu_{e, \mu, \tau}, e, \mu $\end{document} and \begin{document}$ e^-e^+\rightarrow h\gamma $\end{document} in \begin{document}$ U(1)_{B-L} $\end{document} extension of the standard models. In phenomenological results, the signal strengths for \begin{document}$ h\rightarrow \ell \bar{\ell}\gamma $\end{document} at Large Hadron Collider and for \begin{document}$ e^-e^+\rightarrow h\gamma $\end{document} at future Lepton Colliders are analyzed in physical parameter space for both vector and chiral \begin{document}$ B-L $\end{document} models. We find that the contributions from neutral gauge boson \begin{document}$ Z' $\end{document} to the signal strengths are rather small. Consequently, the effects are hard to probe at future colliders. While the impacts of charged Higgs, CP-odd Higgs in the chiral \begin{document}$ B-L $\end{document} model on the signal strengths are significant and can be measured with the help of the initial polarization beams at future lepton colliders.
The production of charmonium pentaquark from b-baryon and B-meson decay: SU(3) analysis
Wei-Hao Han, Ye Xing, Ji Xu
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In this paper, we study the production of charmonium pentaquark \begin{document}$ c \bar c q q q $\end{document} from bottom baryon and B-meson decays under the flavor SU(3) symmetry. Decay amplitudes for various processes are parametrized in terms of the SU(3) irreducible nonperturbative amplitudes. A number of relations between decay widths have been deduced. Moreover, the strong decays of pentaquark is also taken into account. These results can be tested in future measurements at LHCb, Belle II and CEPC. Once a few decay branching fractions have been measured, our work could provide hints for exploring new decay channels or new pentaquark states.
Strong decays of the Pc(4312) and its isospin cousin via the QCD sum rules
Xiu-Wu Wang, Zhi-Gang Wang
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In the present work, considering the conservation of isospin in the strong decays, we investigate the strong decays of the pentaquark molecule candidate \begin{document}$ P_c(4312) $\end{document} and its possible higher isospin cousin \begin{document}$ P_c(4330) $\end{document} in the framework of the QCD sum rules. What's more, the pole residue of the Δ baryon with isospin eigenstate \begin{document}$ |II_3\rangle=|\frac{3}{2}\frac{1}{2}\rangle $\end{document} is obtained. If the possible pentaquark molecule candidate \begin{document}$ P_c(4330) $\end{document} could be testified in the future experiment, it would shed light on interpretations of the \begin{document}$ P_c $\end{document} states.
Revisit spin effects induced by thermal vorticity
Jian-Hua Gao, Shi-Zheng Yang
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We revisit the spin effects induced by thermal vorticity by calculating them directly from the spin-dependent distribution functions. For the spin-1/2 particles, we give the polarization up to the first order of thermal vorticity and compare it with the usual result calculated from the spin vector. For the spin-1 particles, we find that all the non-diagonal elements vanish and there is no spin alignment up the first order of thermal vortcity. We present the spin alignment at second-order contribution from thermal vorticity. We also find that the spin effects for both Dirac and vector particles will receive extra contribution when the spin direction is associated with the particle's momentum.
Exploring dark matter-gauge boson effective interactions at the current and future colliders
Yu Zhang, Yi-Wei Huang, Wei-Tao Zhang, Mao Song, Ran Ding
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In this work, we investigate the collider constraints on effective interactions between Dark Matter (DM) particles and electroweak gauge bosons in a systematic way. We consider the simplified models in which scalar or Dirac fermion DM candidates only couple to electroweak gauge bosons through high dimensional effective operators. Taking into account the induced DM-quarks and DM-gluons operators from the Renormalization Group Evolution (RGE) running effect, we present comprehensive constraints on effective energy scale Λ and Wilson coefficients \begin{document}$ C_B(\Lambda),\,C_W(\Lambda) $\end{document} from direct detection, indirect detection, and collider searches. In particular, we present the corresponding sensitivity from the Large Hadron Electron Collider (LHeC) and the Future Circular Collider in electron-proton mode (FCC-ep) for the first time, update the mono-j and mono-γ search limits at the Large Hadron Collider (LHC), and derive the new limits at the Circular Electron Positron Collider (CEPC).
Solving bound-state equations for scalar and hybrid QCD in two-dimensional spacetime
Xiaolin Li, Yu Jia, Ying Li, Zhewen Mo
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We investigate the bound-state equations in two-dimensional QCD in the \begin{document}$ N_c\to \infty $\end{document} limit. We consider two types of hadrons, an exotic "meson" (which is composed of a bosonic quark and a bosonic anti-quark), and an exotic "baryon" (composed of a fermionic quark and a bosonic antiquark). Using the Hamiltonian operator approach, we derive the corresponding bound-state equations for both types of hadrons from the perspectives of the light-front quantization and equal-time quantization, and confirm the known results. We also present a novel diagrammatic derivation for the exotic "meson" bound-state equation in the equal-time quantization. The bound-state equation for the exotic baryons in the equal-time quantization in two-dimensional QCD is new. We also numerically solve various bound-state equations, obtain the hadron spectrum and the bound-state wave functions of the lowest-lying states. We explicitly demonstrate the pattern that as the hadron is boosted to the infinite-momentum frame, the forward-moving bound-state wave function approaches the corresponding light-front wave function.
Soft pattern of Rutherford scattering from heavy target mass expansion
Yu Jia, Jia-Yue Zhang
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We investigate the soft behavior of the tree-level Rutherford scattering process. We consider two types of Rutherford scattering, a low-energy massless point-like projectile (say, a spin-\begin{document}$ {1\over 2} $\end{document} or spin-\begin{document}$ 0 $\end{document} electron) hits a static massive composite target particle carrying various spins (up to spin-\begin{document}$ 2 $\end{document}), and a slowly-moving light projectile hits a heavy static composite target. For the first type, the unpolarized cross sections in the laboratory frame are found to exhibit universal forms in the first two orders of \begin{document}$ 1/M $\end{document} expansion, yet differ at the next-to-next-to-leading order (though some terms at this order still remain to be universal or depend on the target spin in a definite manner). For the second type, at the lowest order in electron velocity expansion, through all orders in \begin{document}$ 1/M $\end{document}, the unpolarized cross section is universal (also not sensitive to the projectile spin). The universality partially breaks down at relative order-\begin{document}$ v^2/M^2 $\end{document}, though some terms at this order are still universal or depend on the target spin in a specific manner. We also employ the effective field theory approach to reproduce the soft behavior of the differential cross sections for the target particle being a composite spin-\begin{document}$ {1\over 2} $\end{document} fermion.
PARTICLES AND FIELDS
Thermodynamic properties and phase diagram of quark matter within non-extensive Polyakov chiral SU (3) quark mean field model
Dhananjay Singh, Arvind Kumar
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In the present work, we apply Tsallis non-extensive statistics to study the thermodynamic properties and phase diagram of quark matter in the Polyakov chiral SU(3) quark mean field model. Within this model, the properties of the quark matter are modified through the scalar fields \begin{document}$ \sigma, \zeta, \delta, \chi $\end{document}, the vector fields \begin{document}$ \omega, \rho $\end{document}, ϕ, and the Polyakov fields Φ and \begin{document}$ \bar{\Phi} $\end{document} at finite temperature and chemical potential. Non-extensive effects have been introduced through a dimensionless parameter q and the results are compared to the extensive case (\begin{document}$ q\rightarrow 1 $\end{document}). In the non-extensive case, the exponential in the Fermi-Dirac (FD) function is modified to a q-exponential form. The influence of q parameter on the thermodynamic properties: pressure, energy, and entropy density as well as trace anomaly is investigated. The speed of sound and specific heat with non-extensive effects is also studied. Furthermore, the effect of non-extensivity on the deconfinement phase transition as well as the chiral phase transition of \begin{document}$ u, d, $\end{document} and s quarks is explored. We found that the critical end point (CEP), which defines the point in the \begin{document}$ (T - \mu) $\end{document} phase diagram where the order of the phase transition changes, shifts to a lower value of temperature, \begin{document}$ T_{CEP} $\end{document}, and a higher value of chemical potential, \begin{document}$ \mu_{CEP} $\end{document}, as the non-extensivity is increased, i.e., \begin{document}$ q> $\end{document}1.